1. Technical Field
The present invention relates to a data encryption apparatus.
2. Background Art
A data encryption apparatus is used when, for example, encrypting content such as digitally converted music and video and distributing the encrypted content. There is demand for a high level of security when distributing content etc. To increase the level of security, it is effective to increase the degree to which the data targeted for distribution is scrambled.
For example, patent document 1 discloses a data encryption method for realizing high scrambling performance.
In the technology of patent document 1, input data is scrambled by splitting the input data into a plurality of blocks of the same data length, performing at least one of an exclusive OR operation, an addition operation, and a remainder operation using the data blocks, performing substitution processing (conversion processing using a table) on the results, and concatenating the data resulting from the substitution processing.    Patent document 1: Japanese Patent Application Publication No. S62-113191
However, the above conventional technology requires a large number of substitution processes in order to realize high scrambling performance, and realizing this large number of substitution processes with hardware requires a large number of gates, which makes it impossible to reduce the hardware gate scale.
In view of the above problem, an aim of the present invention is to provide a data encryption apparatus that realizes high scrambling performance while reducing the hardware gate scale over conventional technology.